I believe I predicted, in my gradeschool years, that the banning of my mom's aerosal hairsprays in the 70's as a solution for the dreaded ozone "hole" would lead to catastrophic threats of warming in the upcoming non-democrat administrations of the 00's. Nice to see my prediction proven by science.

Just kidding. But I do believe that this is just further evidence of how complex the situation is and how "fixing" one thing, may lead to other "problems". Good information.

The 'aerosol' in hairspray cans is not the same 'aerosol' you see from space. Aerosol cans were banned because they used CFCs as a propellant. (Many times more CFC were used in Air Conditioners, but that industry had a stronger lobby). The aerosol you can see from space is mostly sulfate aerosol which comes from burning coal. This aerosol has been declining since the 70s and the passing of the clean air act. Thus Darren is right that solving one problem can create others, or at least reveal others, but it has nothing to do with hairspray.

I agree with you. I've always thought it would be useful to bann aerosols... now I find out it contributes to GW. I'm more confused than ever...

Ahh, lads, better the devil you know than the devil you don't. You have to look long and hard, from all sides, before you decide on a path of action that could cost a lot of people, a lot of cash, jobs, relocation, etc.

The final test to see if important statements will weather the storm, is to try everything possible, by all (including those who made the statement), to disprove it. Once "all" avenues have been exhausted and it passes, then onward we go. That's something that rarely happens in government and science anymore. Unfortunately, some peer review is based on the old "buddy system".

Note the following comment in the article:

"The scientists describe their results as a likely trend because the National Oceanic and Atmospheric Administration satellite sensors they used in their analysis were not specifically designed to observe aerosols, and may contain some errors."

Do the observations also include the effect of cloud cover? If so, the observations could mostly be measuring a reduction in effective cloud cover, which would support the cosmic ray theory of global warming.

Even if the effects of clouds have been removed, it is quite likely that the major change in optical thickness has nothing to do with human produced aerosols. Note that the biggest reductions are in equatorial regions, especially west of the Sahara and around the Arabian Peninsula. I know that in recent years there has been a dramatic increase in rainfall and vegetation in the Sahara, which leads to less atmospheric dust. Perhaps the same thing has occurred on the Arabian Peninsula?

Also note that in the lee of the most industrialized parts of the world, there have been relatively small reductions and even some increases. Also note that the lifetime of most atmospheric aerosols is a few days at most. It is hard to imagine how industrial aerosols, produced at high latitudes, make it all the way to equatorial regions in just a few days.

I understand that aerosols are essential for cloud droplet formation. Fewer aerosols imply fewer clouds, or at least less dense clouds. However, it is very hard to believe that industrial aerosols have had a measurable affect on tropical cloud cover. Especially over the Pacific Ocean?!

Amusing that this shows exactly how following indicators (like paleoclimate measures of temperature and atmospheric carbon) work. The peak use of coal and other general aerosol pollution was in the 60s, followed by the global cooling "ice age" scare of the 70s. Now as the cloud producing aerosols are being further reduced and more solar energy no longer gets reflected, global temperatures are _finally_ getting warmer.

Lest ya'll think I was serious, I was joking about the hairspray thing. Though it does bring up a point that translates to the pervading GW theories.

While we all were told that CFC's were represented as a likely cause of the ozone hole, I never did hear how the CFC's at altitude 6'-0" magically reached upper atmospheric altitudes (say 100,000 feet or greater) to do their dirty work. I often wonder about how the CO2 emitted from the back of my nasty SUV at elevation 3'-0" cause similar problems. Especially as CO2 is heavier than air and tends to sink unless acted upon by some other force.

Maybe someone can enlighten me on that. I would greatly appreciate it.

Darren,
Gee man, get with the times. Either it is a Gaia Thang (TM) or it uses the Force, take your pick.

I always enjoyed the boohoo over too much CO2, since I spent some time working with hydroponics and a nice bit of profit was selling gear to enhance the CO2 concentration around growing things. It seems it made them grow bigger, faster and produce better crops.